State Route 158 is a two-lane north–south state highway located in the central portion of the U.S. state of Ohio. State Route 158's southern terminus is in downtown Lancaster at its junction with U.S. Route 22, State Route 37 and State Route 188. Its northern terminus is at a T-intersection US 40 in Kirkersville.

State Route 37 is a northwest-southeast highway in Ohio. It is the ninth longest state route in Ohio. Its western terminus is at U.S. Route 224 and SR 12 in Findlay, and its eastern terminus is at SR 60 and SR 78 in McConnelsville.